: breaking dormancy, increasing stem length, and reducing production time ( Naranja and Balladares, 2008 ). Because GA 3 effects can vary greatly among different taxa, the objective of these trials was to quantify the effects of GA 3 on cut stem production
Ben A. Bergmann, John M. Dole, and Ingram McCall
H. Chris Wien
The stems of many flower species used as cut flowers are too short to be commercially useful. Non-chemical techniques are needed to increase the length of the harvested stems without weakening stem strength. Field experiments were conducted that explored the use of black or red shade fabric, used either as a canopy, or as a side curtain, with three species of cut flowers. Trachelium caerulum, Eustoma grandiflorum (Echo Champagne), and Rudbeckia hirta (Prairie Sun) were grown in split-plot experiments in which shade and shelter treatments were applied as main plots, and the flower species formed the subplots. In 2004, shade canopies of 70% light transmission were compared in black and red (“ChromatiNet”) netting, and 50% red netting. Stem length increased from 51 cm for unshaded controls to 54, 56, and 59 cm for 70% black, red, and 50% red, respectively. Productivity of the plants was decreased an average of 21% by shading. In 2005, shade canopies of 50% black or red were compared to side curtains of the same materials, and an unsheltered control, growing the same species of flowers. Stem length was increased by 25% when plants were grown under a shade canopy, and by 14% in the side curtain plots. Shading treatments reduced stem yield by 31%, whereas side curtains had no significant effect on number of stems per plant. Color of the netting did not affect stem length or stem yield in 2005. In both years, the thickness of harvested stems were increased significantly in the shelter treatments. The three species reacted similarly to the treatments imposed in both years. Shelter treatments can be a practical way of increasing cut flower stem length.
John M. Dole, Janet C. Cole, and Vicki Stamback
Rooted cuttings of four woody cut species, Buddleia davidii `Black Knight' (butterfly bush), Forsythia × intermedia `Lynwood Gold', Salix chaenomeloides (Japanese pussywillow), and Salix matsudana `Tortuosa' (corkscrew willow) were planted outdoors in 23 Apr. 1992. During the next year, forsythia, pussywillow, and corkscrew willow plants were either unpruned or pruned to 30–45 cm above the ground: 1) during dormancy or immediately after harvest (winter); 2) 3 to 4 weeks after start of shoot growth (spring); or 3) in early June (summer), and number and length of stems harvested was recorded for three years. Butterfly bush was either unpruned or pruned to 8 cm above the ground during: 1) winter or 2) spring, and number and length of stems recorded for 2 years. Stem length and number increased each year for all four species, and all species produced harvestable stems within 1 year after planting. For forsythia, no differences due to treatment were found, although year by treatment interactions were noted. The unpruned control produced the longest and greatest number of stems for pussy willow. Winter or spring pruning produced the longest and greatest number of stems for corkscrew willow. For butterfly bush, spring or no pruning produced the greatest number of stems, and year by treatment interactions were noted.
Alicain S. Carlson and John M. Dole
( Rees, 1974 ). Increasing planting density to increase productivity per unit area can decrease the productivity per plant, increase stem length, and increase earliness of flowering depending on the species ( Rees, 1974 ). Higher rates of transpiration
W. Garrett Owen, Alyssa Hilligoss, and Roberto G. Lopez
random from each block to determine the following quality measurements: stem length and caliper, and flower number, length, and width. Stem marketability was determined by length (greater than 30 cm) and flower quality (no visual defects). Stems shorter
Tong Geon Lee, Samuel F. Hutton, and Reza Shekasteband
hold fruit up off the ground (e.g., fruit remain on the raised plastic beds) without the support of stakes is expected to directly contribute to tomato industries. To address this, the stem length should be reduced without negatively affecting fruit
Anke van der Ploeg, Ranathunga J.K.N. Kularathne, Susana M.P. Carvalho, and Ep Heuvelink
fresh and dry weight (ventilated oven, 105 °C for at least 15 h), number of leaves on the main stem, number of flowers (including flower buds larger than 5 mm), and stem length were determined. Total plant leaf area and individual flower area of the
Junne-Jih Chen, Yung-Wei Sun, and Tzay-Fa Sheen
Seedlings of tomato (Lycopersicon esculentum Mill.) and cabbage (Brassica oleracea L. var. Capitata) were planted in 240-cell plug trays in the greenhouse and subjected to irrigation with water at different temperatures once a day. Irrigation with cold (5 to 15 °C) water reduced stem length of tomato by 28% to 32% in comparison with irrigation with water at room temperature (27.5 to 30.5 °C). Use of water at 10 °C did not affect total shoot dry weight but increased the shoot dry weight per centimeter of stem. Irrigation with water at 5 °C reduced stem length of cabbage seedlings 40%, but use of water at 10 and 15 °C did not. Both shoot and root dry weights were increased by irrigation with water at 10 °C. These results demonstrate that irrigation with cold water provides an effective method for improving the quality of plug-grown seedlings.
S.P. Vander Kloet and J. Pither
Periodic prescribed burns of lowbush blueberry barrens promote high yield, aid in weed control, and reduce fungal and insect damage. Whether such prescribed fires should be set in the autumn or the spring has been a matter of some dispute. Previous research on Vaccinium angustifolium Aiton suggested some advantages to autumnal burning, but few data have been collected on V. myrtilloides Michaux. To evaluate whether time of burning affected plant qualities most favorable for mechanical harvesting, such as stem length and lateral branching, a series of experiments was conducted on V. myrtilloides. Differences in stem length, numbers of lateral branches, and buds per stem were nonsignificant among plants burned in fall vs. those burned in spring. In three of four experiments, however, fall burns resulted in the growth of fewer lateral branches. Furthermore, among the four experiments, growth responses were more uniform following fall than following spring burns. We therefore suggest that, where possible, fall burns should be prescribed for blueberry plants that will be mechanically harvested.
Various field-grown specialty cut-flower species were subjected to full sun or 55% or 67% shade treatments for 2 to 3 years. Plants grown in shade had longer flower stems than those grown in ambient irradiance; however, yield (flower stems per plant) was species-dependent. Yield of Centaurea americana Nutt. `Jolly Joker', an annual speices, and Eryngium planum L., a perennial, declined linearly with each reduction in irradiance. However, yield of Echinops ritro L. `Taplow Blue', a perennial species, was higher in 55% shade than in ambient irradiance. Yield of transplants and tubers of Anemone coronaria L. `De Caen' were not affected by planting material (transplants or tubers). Plants grown under 67% shade had the longest stems starting 3 weeks after the beginning of harvest and the difference persisted for an additional 4 weeks regardless of planting material. A quadratic decline in yield in three of four cultivars of Zantedeschia Spreng. occurred as shade increased, but yield was similar for ambient and 55% shade. Scape length and spathe width increased as shade increased, although some cultivars were more responsive than others.